Microelectronics chips such as integrated circuits are made from comparatively large wafers of semiconductor material. This process typically involves multiple successive steps including the following: generation of an etch mask photolithographically; etching of a layer of material as defined by the mask; removal of the photolithographic mask through some combination of wet and dry chemical techniques; and deposition of layers of materials. The photolithographic mask is formed from a polymeric material called a photoresist. After the photoresist mask has been removed, a final cleaning step, called rinsing or wet cleaning, is typically performed.
Deionized (DI) water is known for its use in this rinsing of semiconductor devices. It is known to prevent any metal corrosion and contamination of the devices. In order to make the wet cleaning more effective, gases such as carbon dioxide (CO2) and nitrogen (N2) have often been mixed with the DI water. Rinsing with carbonated deionized (DI-CO2) water is an electrically inert process that allows for damage free cleaning while maintaining the device integrity.
Controlling the proportions of these gases require considerably complex instrumentation and high costs which are significant disadvantages of current methods. Typically, an excess of gas is used which can lead to toxicity and disposal problems with respect to the unused gases particularly carbon dioxide. As a result, these processes are expensive and cumbersome.